Whisk the liquids and eggs together, then whisk in the flour, salt and butter, making sure there are no lumps. This has always worked fine for me, but Julia Child recommends using the blender to whip everything together. A real French cook would also say to refrigerate the batter for at least an hour or two, to let the flour soak up the liquids. If you use whole wheat or buckwheat flour (which I highly recommend!) this might be a good idea, but your crepes won't turn out horrible even if you don't. The batter should be a creamy liquid.

Technique is fairly important in making crepes. Heat a skillet over medium-high heat, and brush with oil. When the pan is very hot, just barely smoking, hold it in one hand away from the heat and with your other hand pour in about a 1/4 cup scoop of batter. Quickly tilt the pan around so that the batter flows out to the edges in a thin (about 1/16 inch) film. Put the pan back on the burner and cook 1-2 minutes, until the crepe is lightly browned on the bottom. Then flip it over to lightly brown the other side. Slide the crepe onto a plate, brush the skillet with oil again, and repeat! Don't be afraid to make the full recipe, because it's always easy to use up extra crepes - just wrap up any kind of leftovers in them for lunch, or some fresh fruit or other sweet stuff for a dessert/snack.

Melt the butter over low heat. Stir in the flour, keep stirring as it froths up, and cook for another minute or two, but make sure it doesn't brown! Remove from the heat, and vigorously whisk in the liquid. Return to the heat and keep stirring until it comes to a boil. Keep the sauce hot until you are ready to pour it over the spinach.

Put a handful of spinach leaves on a crepe, pour the hot veloute over them, and roll it up quickly. Make three or four of these per person, then drizzle a bit more sauce over the outside. Delicious!